After some routine and unrelated work in the engine compartment, the car won't start.



The details of not starting are these:

• There is power to the ignition coil.
• There is power to the starter and the engine will turn over
• There is the normal sound of the fuel pump pressurizing
• VATS at the lock cylinder is currently bypassed with the proper resistor
• There is no power leaving the ignition coil to go to the distributor for spark
• There is no sound of fuel injectors working
• There is no "Check Engine" light (Does this mean that code 53 isn't being thrown? I don't have an ODB2 tester available.)

Is anyone able to translate these details into a working fix? From what I can tell we've chased the problem into a corner and now we still can't find it! If there's no error then the ECM says everything's fine. The VATS isn't a problem because it's bypassed (and the ECM confirms it by not giving an error). There's power everywhere there should be... What else could be broken here?

 

If it were VATS, the starter would not turn (generally), so for now I'd rule that out.

I'd look more to the no spark issue (no voltage from coil) which is also not VATS related.

Knowing what year, engine, induction system would help us help you more.

 

I have a 90 IROC with TPI. It's a convertible so it came with a 305, but I've put in a 350 when the original needed a rebuild.

I guess I'm looking for an ECM output that is going to regulate the operation of both the ignition coil output and the fuel injectors?

 

http://www.austinthirdgen.org/index.php?pid=19

That's wiring diags for most all 3rd gens - some ECM wiring and pinouts as well - maybe that will help

 

Yeah I've seen the wiring diagram but I don't know which wires to look at now!

I just checked the injectors' resistances on the off chance that one would read low and fool the ECM into thinking there was a short. They all read ~16.6 ohms which seems slightly high from what I've read, but the uniformity of the readings and the crapitude of my DVOM makes me think that isn't the problem.

I've got something blocking voltage from the secondary ignition coil and something blocking my injectors from pulsing. I imagine these troubles must be related. Does anyone know what wires on the engine diagram I should investigate here? There's gotta be one stupid little wire that isn't sending the right signal and it's jamming up all these other functions. (Right?)

 

Resolution:

The two prong connector that goes to the MAT sensor looks an awful lot like the two prong connector that goes to the ignition module. Unfortunately the car doesn't want to work when you have plugs in the wrong places.

Thanks for the attempted helps!